Paint removers or strippers are well known in the art. One class is based on methylene chloride, usually consisting of 60-80% methylene chloride along with methanol, surfactants, emulsifiers and alkaline or acid activators. Toxic concerns have led to the requirement that these strippers carry warning labels. Some industrial users are believed to be using strippers based on N-methyl pyrrolidone (NMP) which are inherently much more expensive than methylene chloride-based strippers and reportedly not as effective. So also, it may be desirable to limit usage of NMP since it has recently been implicated as potentially causing reproductive damage.
Yet other classes of paint strippers are based on aromatic hydrocarbons, methanol, toluene, acetone, alkali and the like.
In general, it is desirable that a paint remover have a relatively high flash point (low flammability) and not be subject to photochemical decomposition or excessive fuming. Moreover, vapors, especially toxic vapors, are particularly problematical. The 3M Corporation has begun to sell "Safest Stripper" which is believed to be based on dimethyl adipate and is claimed to be non-toxic. It is reported, however, that this product is slow-acting and has accordingly produced a negative reaction from consumers. Still other strippers, such as caustic soda based compositions require relatively high temperatures to be effective and are thus unsuitable for many applications.
With concerns for abatement of lead paint-related environmental problems, the search for paint removers with low flammability and low toxicity as well as relatively high effectiveness continues.
Trioxane-containing paint strippers have been suggested, notably in U.S. Pat. Nos. 4,956,115; 4,973,420 and 4,830,772. The '420 and '772 patents disclose compositions which appear to have relatively low flash points, while the '115 patent discloses multi-phase emulsions in water where preparation and stability may be a problem.